An object possess absolutely ... AC working intensively wrists, forearms, hands (grip). Little we used 5 minutes per day we see its scores rise ... the counter top allows to establish scores of the left hand or draoite and pass a buddy to kil trying to do better .. It is very addictive, and because we too lazy to revive the ball with rope well we made sure she does not stop until we no arm numb / exhausted / burning choice . No worries for those with fragile wrists or creaky, the ball is progressive and works only if one of the circles of the wrist that makes the strongest (carpal tunnel syndrome). Must start at with the rope, like start a chainsaw but after it is excellent. No battery for LED is a dynamo.
